This application claims the benefit of German Application 100 32 354.5, filed Jul. 4, 2000, herein incorporated by reference.
The present invention relates generally to a thermostat valve for a coolant circuit of an internal combustion engine, and more particularly to such a valve having a stationary housing containing an electrically heatable thermostatic element operating a work piston which, in turn, acts on a valve element, which forms a cage-like surrounding to the housing and has a plate-like valve seat flange sealed with respect to the housing, against the loading force of a restoring spring supported on an abutment.
A thermostat valve of the type described above is known from German Patent Publication DE-A 42 33 913. Such a thermostat valve has the advantage that the housing of the thermostatic operating element, into which electrical connections are placed, is arranged to be stationary, so that the electrical connections are not forced to follow movements, and can furthermore be arranged outside of the flowing coolant.
It is an object of the present invention to further improve the above-described type of thermostat valve in such a way that it is independent to a large extent from the structural arrangement of a housing in which it is installed.
This object is attained by providing a base plate to which the housing of the operating element and the abutment for the restoring spring are attached.
In this manner, the essential elements of the thermostat valve constitute an insert, which internally absorbs the support forces of the housing of the thermostat operating element and of the abutment for the restoring spring, so that no forces of significance are introduced into a housing in which this thermostatic valve is intended to be placed. As a result, substantial freedom results for the structural design of such a housing.
It is furthermore advantageously provided that the base plate has a valve seat assigned to the plate-like flange of the valve housing. In this way, all functional elements are parts of the insert.
In a further aspect of the invention, the base plate is provided with an inner collar, which is connected by means of strips and on which the housing of the thermostatic operating element is maintained. A very compact construction thereby results.
It is provided in a further feature of the invention that the housing is equipped with an annular shoulder, which receives a seal ring, which is assigned to a neck connected with the plate-like flange of the valve element. In this manner, a dependable seal is achieved between the valve element and the housing of the operating element. It is further useful to support the inner collar of the base plate on the annular shoulder of the housing of the thermostatic operating element. This annular shoulder thereby performs a second function in this manner.
It is also provided in a further aspect of the invention that the base plate is fastened on a housing element, which is provided with at least one connector for the coolant circuit and one lead for electrical lines. In this way, the thermostat valve constitutes a connecting element, which can be connected to an engine block or a like mounting without elaborate assembly work being required. In a further arrangement, the end of the housing of the thermostatic operating element facing away from the work piston is inserted into a cap-like guide of the housing element, which is preferably made of plastic. This cap-like guide is used, on the one hand, for holding the thermostatic operating element, and on the other hand, also for the thermal insulation of the thermostatic operating element, in particular against cold coolant, so as to reduce the loss of energy when the thermostatic operating element is heated.
Further characteristics and advantages of the invention ensue from the following description of the embodiment represented in the drawings.